NASA Advisory Committee

ScienceNow has more on the NAC firings: NASA Chief Blasts Advisors

Now, you can read this two ways: on the one hand the NAC has a purpose, set by NASA, and its members should stick to their function; on the other hand, the NAC is there to advise, even, or especially, when the advise is unwelcome.

One of the great strengths of democracy, historically, is that it has structures which provide negative feedback and correct political processes gone awry, eventually.
Destroying those structures destroys the functional advantage of the system.